CRITERIA FOR PERFORMING CALIBRATION AND INTERMEDIATE CHECKS ON EQUIPMENT USED IN ACCREDITED FACILITIES

Transcription

1 CRITERIA FOR PERFORMING CALIBRATION AND INTERMEDIATE CHECKS ON EQUIPMENT USED IN ACCREDITED FACILITIES Prepared by: Technical Manager Approved by: Chief Executive Officer Approval Date: Effective Date:

2 Table of Contents 1. PURPOSE AND SCOPE GENERAL SADCAS Policy on Metrological Traceability Reference Materials/Consensus Standards In-house Calibrations Requirements for Calibration Intermediate Checks Non-accredited Calibration Service Providers... 6 Page 3. REFERENCES... 6 APPENDIX - AMENDMENT RECORD... 7 Page 2 of 10

3 1. PURPOSE AND SCOPE The purpose of this document is to specify criteria for performing calibration and intermediate checks on equipment used in facilities accredited by SADCAS. This document applies to all SADCAS accredited facilities. 2. GENERAL 2.1 SADCAS Policy on Metrological Traceability Calibration laboratories Equipment and reference standards used by calibration laboratories and having an impact on the accuracy and validity of measurement result shall be calibrated by: a) A National Metrology Institute (NMI) whose service is suitable for the intended need and belongs to the CIPM MRA and are signatories to its Mutual Recognition Agreement (MRA) amongst NMIs and who have approved CMCs within the BIPM Key Comparison Database (KCDB) which includes the range and uncertainty for each listed service. b) A calibration laboratory accredited by an accreditation body covered by the ILAC Arrangement or by Regional Arrangements recognized by ILAC whose service is suitable for the appropriate calibration. c) An NMI whose service is suitable for the intended need but not covered by the CIPM MRA. The National Metrology Institute shall have participated in the SADC Cooperation in Metrology (SADCMET) through which SADC countries that are not yet signatory to the CIPM can get their traceability. The acceptance of other NMIs other than those of the CIPM MRA partners shall be at the discretion of SADCAS Chief Executive Officer after due consultation of the appropriate Advisory Committee subject to satisfactory evidence of the technical competence of the laboratory using appropriate methods as outlined in the technical procedures. d) A calibration laboratory whose service is suitable for the intended need but not covered by the ILAC Arrangement or by regional arrangements recognized by ILAC. For options c) and d) appropriate evidence for the technical competence of the laboratory and claimed metrological traceability shall include the following: - Record of calibration method validation; - Procedures for estimation of uncertainty ; - Documentation for traceability of measurements; - Documentation for assuring the quality of calibration results; Page 3 of 10

4 - Documentation for the competence of staff; - Documentation for accommodation and environmental conditions; and - Audits of the calibration laboratory. Options a) and b) above are the preferred options for metrological traceability. Options c) and d) are only applicable when options a) and b) are not possible Testing/medical laboratories Equipment and instruments used by testing and medical laboratories and having a significant impact on the measurement results shall be calibrated by one of the processes defined in 2.1.1; and Where traceability as stated above is not technically possible or reasonable or available, the testing/ medical laboratories and client and other interested parties may agree to using reference materials /certified reference materials as outlined in Traceability for Inspection Bodies Equipment used by inspection bodies and having significant impact on measurement results shall be calibrated. SADCAS accepts evidence of traceability as outlined in Where traceability as stated above is not technically possible or reasonable or available, the inspection body and client and other interested parties may agree to using reference materials /certified reference materials as outlined in Reference Materials / Consensus Standards SADCAS acknowledges that it is not always possible or realistic to expect all measurements to be traceable to the International System of Units (SI), for example, traceability may be to a Certified Reference Material (CRM), or a specified method and/or consensus standard. Participation in a suitable program of interlaboratory comparisons / proficiency testing is a requirement. Where traceability is established through the use of reference materials, traceability is accepted if the Reference Materials (RMs) are included in the BIPM KCDB, or have been produced by a competent Reference Material Producer (RMP). Where RMs are covered by the Joint Committee for Traceability in Laboratory Medicine (JCTLM), these are also considered as having established valid traceability. Where reference materials do not meet the above criteria, they are required to be treated as critical consumables, and the facility is required to demonstrate that each RM is suitable for its intended use. Page 4 of 10

5 2.3 In-House Calibrations In-house calibrations are considered as being those calibrations performed by a facility on their own premises on their own test and measurement equipment. For all in-house calibrations the facility is required to maintain as a minimum the following: a) a documented calibration procedure or method; b) a calibration certificate or report, or some other suitable method of recording the calibration and measurement data; c) appropriate educational and training records to demonstrate the competence of the personnel performing the calibration; d) copies of certificates and reports to demonstrate traceability to the SI system of units or RMs as per 2.1 & 2.2 above; e) all reference standards and measuring instruments shall be calibrated at appropriate intervals, the facility shall have and apply a procedure for establishing these calibration intervals; and f) a procedure for the estimation of the measurement uncertainty, which shall be applied for at least each type of calibration. The uncertainty of measurement shall be taken into account when making a statement of compliance. As calibration laboratories are accredited for the purpose of passing on metrological traceability through an unbroken chain of comparisons, in-house calibration by a calibration laboratory is only acceptable where the laboratory has been accredited for the specific in-house calibration performed. Where equipment within a calibration laboratory is used solely as a transfer device it is not necessary for the laboratory to be accredited for the calibration of this transfer device. For example, when a balance is used to calibrate weights and the process of the calibration involves the process of the comparison of two weights, the standard and the unit under test, it is not necessary that the laboratory be accredited for the calibration of the balance which is used solely as a transfer device. 2.4 Requirements for Calibration All equipment and measuring instruments used to perform testing and measurement within a facility, including subsidiary measurements, must be calibrated unless it can be demonstrated that they have an insignificant effect on the accuracy or validity of the measurement result. Records shall be available that demonstrate this. For the purposes of interpretation any item of test and measurement equipment, the uncertainty of which contributes less than 5% to the total uncertainty of measurement would be considered as insignificant. Page 5 of 10

6 2.5 Intermediate Checks Intermediate checks are those checks performed to maintain confidence in the calibration status of measuring and test equipment. Intermediate checks shall be conducted according to a defined procedure. Intermediate checks are not a substitute for calibration but may provide justification for the extension of calibration intervals, where results are favourable. When intermediate checks are performed appropriate records shall be maintained and the uncertainty of measurement shall be considered when confirming if the calibration status continues to satisfy the requirements for the test or measurement. 2.6 Non-accredited Calibration Service Providers The use of non-accredited service providers, or service providers not meeting the requirements for traceability as per clause 2.1 above, are only permitted where no alternative accredited service provider is currently available. The use of such service providers is subject to the same requirements as for in-house calibrations and to satisfactory evidence of the technical competence of the service provider using appropriate methods as outlined in the technical procedures and records of which must be available at the facility accredited or seeking accreditation. The following methods may be used as appropriate and feasible: a) Participation in a suitable programme of inter laboratory comparisons; b) Use of suitable reference materials certified to indicate the characterization of the material; c) Examination or calibration by another procedure; d) Ratio or reciprocity type measurements; e) Mutual consent standards or methods which are clearly established, specified, characterized and mutually agreed upon by all parties concerned; and f) Documentation of statements regarding reagents, procedures or the examination system when traceability is provided by the supplier or manufacturer. 3. REFERENCES SADCAS PM 01 - SADCAS Policy Manual SADCAS TG 01 - Information to Organizations Applying for Accreditation SADCAS TR 02 - Accreditation Requirements ILAC P 10: ILAC Policy on the Traceability of Measurement Results ILAC P 14: ILAC Policy for Uncertainty in Calibration Page 6 of 10

7 APPENDIX - AMENDMENT RECORD Revision Status Page Clause/ Subclause Change Description of Change Approved by Effective Date Issue CEO Issue Deleted sub clause in its entirety and substituted with the following: Equipment and reference standards used by calibration laboratories and having an impact on the accuracy and validity of measurement result shall be calibrated by: CEO a) A National Metrology Institute (NMI) whose service is suitable for the intended need and belongs to the CIPM MRA and are signatories to its Mutual Recognition Agreement (MRA) amongst NMIs and who have approved CMCs within the BIPM Key Comparison Database (KCDB) which includes the range and uncertainty for each listed service. The acceptance of other NMIs other than those of the CIPM MRA partners shall be at the discretion of SADCAS Chief Executive Officer after due consultation of the appropriate Advisory Committee. b) A calibration laboratory accredited by an accreditation body covered by the ILAC Arrangement or by Regional Arrangements recognized by ILAC whose service is suitable for the appropriate calibration. c) An NMI whose service is suitable for the intended need but not covered by the CIPM MRA. The National Metrology Institute shall have participated in the SADC Cooperation in Metrology (SADCMET) through which SADC countries that are not yet signatory to the CIPM can get their traceability. d) A calibration laboratory whose service is suitable for the intended need but not Page 7 of 10

8 Revision Status Page Clause/ Subclause Change Description of Change Approved by Effective Date covered by the ILAC Arrangement or by regional arrangements recognized by ILAC. For options c) and d) appropriate evidence for the technical competence of the laboratory and claimed metrological traceability shall include the following: - Record of calibration method validation; - Procedures for estimation of uncertainty ; - Documentation for traceability of measurements; - Documentation for assuring the quality of calibration results; - Documentation for the competence of staff; - Documentation for accommodation and environmental conditions; and - Audits of the calibration laboratory. Options a) and b) above are the preferred options for metrological traceability. Options c) and d) are only applicable when options a) and b) are not possible. 6 3 Added to list of references ILAC P 10: ILAC Policy on the Traceability of Measurement Results; and ILAC P 14: ILAC Policy for Uncertainty in Calibration CEO Issue 2 3 New Sub clause Sub clause 2.1 (a) renumbered (a) 4 New Sub clause After Heading of 2.1 added another heading which reads Calibration laboratories 2 nd paragraph Inserted subject to satisfactory evidence of the technical competence of the laboratory using appropriate methods as outlined in the technical procedures after Advisory Committee After 2.1 (d) renumbered (d) added new sub clause which reads Testing/Medical Laboratories a) Equipment and instruments used by testing and medical laboratories and CEO CEO CEO Page 8 of 10

9 Revision Status Page Clause/ Subclause Change Description of Change Approved by Effective Date having a significant impact on the measurement results shall be calibrated by one of the processes defined in 2.1.1; b) If the calibration is not a dominant factor in the test result, traceability does not need to be demonstrated but the laboratory shall have quantitative evidence to demonstrate that the calibration contributes insignificantly to the measurement result and the measurement uncertainty of the test st paragraph Lines 4 and 5 Between calibrations and records inserted and to satisfactory evidence of the technical competence of the service provider using appropriate methods as outlined in the technical procedures and Inserted new 2 nd paragraph which reads The following methods may be used as appropriate and feasible: a) Participation in a suitable programme of inter laboratory comparisons; b) Use of suitable reference materials certified to indicate the characterization of the material; c) Examination or calibration by another procedure; d) Ratio or reciprocity type measurements; e) Mutual consent standards or methods which are clearly established, specified, characterized and mutually agreed upon by all parties concerned; and Documentation of statements regarding reagents, procedures or the examination system when traceability is provided by the supplier or manufacturer. Issue a) Deleted second paragraph. c) Added second paragraph which reads: The acceptance of other NMIs other than those of the CIPM MRA partners shall be at the discretion of SADCAS Chief Executive CEO Page 9 of 10

10 Revision Status Page Clause/ Subclause Change Description of Change Officer after due consultation of the appropriate Advisory Committee subject to satisfactory evidence of the technical competence of the laboratory using appropriate methods as outlined in the technical procedures. Issue Added new sub clause Traceability for Inspection Bodies which reads: Equipment used by inspection bodies and having significant impact on measurement results shall be calibrated. SADCAS accepts evidence of traceability as outlined in Approved by Effective Date CEO Where traceability as stated above is not technically possible or reasonable or available, the inspection body and client and other interested parties may agree to using reference materials /certified reference materials as outlined in 2.2. Issue Deleted 2 nd paragraph and substituted with Where traceability as stated above is not technically possible or reasonable or available, the testing/ medical laboratories and client and other interested parties may agree to using reference materials /certified reference materials as outlined in 2.2. CEO Page 10 of 10